Image processing apparatus for endoscope and endoscope system

Abstract

An image processing apparatus for an endoscope includes an image acquisition circuit configured to acquire an image captured by using the endoscope, an interference area setting circuit configured to set, on the image, an interference area having a different characteristic from an observation target in the image, and an interference area corrector configured to perform correction on the image, the correction including a reduction in luminance of the interference area. The interference area setting circuit includes an interference candidate area extractor configured to extract at least one interference candidate area based on the different characteristic from the observation target, and an interference area selector configured to select the interference area from the at least one interference candidate area based on luminance distribution in the at least one interference candidate area.

What is claimed is: 
     
       1. An image processing apparatus for a three-dimensional endoscope, the image processing apparatus comprising:
 an image acquisition circuit configured to acquire a pair of images captured by using the endoscope; 
 an interference area setting circuit configured to set, on an image among the pair of images, an interference area which is different from an observation target in the image with respect to a first characteristic, the first characteristic being a characteristic relating to color; and 
 an interference area corrector configured to perform correction on the image, the correction comprising (i) specifying pixels in the image corresponding to the interference area as processing targets, and (ii) performing image processing to reduce luminance values of the pixels in the image specified as the processing targets, 
 wherein the interference area setting circuit includes:
 an interference candidate area extractor configured to extract at least one interference candidate area based on the first characteristic, and 
 an interference area selector configured to select the interference area from the at least one interference candidate area based on positional information of the at least one interference candidate area in the image and an occupation percentage of areas having pixels with luminance values equal to or higher than a threshold value in the at least one interference candidate area, and 
 
 wherein the interference area selector is configured to select, as the interference area, an interference candidate area that is in contact with a side of the image and that extends from a peripheral edge of the image towards an inside of the image. 
 
     
     
       2. The image processing apparatus according to  claim 1 , wherein the interference candidate area extractor is configured to use chroma information as the first characteristic. 
     
     
       3. The image processing apparatus according to  claim 1 , wherein the interference candidate area extractor is configured to use hue information as the first characteristic. 
     
     
       4. The image processing apparatus according to  claim 1 , wherein the interference area selector is configured to select the interference area from the at least one interference candidate area based on a size of the at least one interference candidate area. 
     
     
       5. The image processing apparatus according to  claim 1 , wherein the correction further comprises performing image processing to reduce chroma of the interference area. 
     
     
       6. The image processing apparatus according to  claim 1 , wherein the interference area corrector is configured to determine the threshold value based on a histogram of luminance values of pixels in the at least one interference candidate area. 
     
     
       7. The image processing apparatus according to  claim 1 , wherein the interference area setting circuit is further configured to set, on each image of the pair of images, the interference area to include an area captured only on the image of the pair of images. 
     
     
       8. The image processing apparatus according to  claim 7 , wherein the correction further comprises performing image processing to reduce chroma of the interference area. 
     
     
       9. An endoscope system comprising:
 the image processing apparatus according to  claim 1 ; and 
 the endoscope. 
 
     
     
       10. The image processing apparatus according to  claim 1 , wherein the interference area comprises an area of a procedure tool. 
     
     
       11. An image processing apparatus for a three-dimensional endoscope, the image processing apparatus comprising:
 an image acquisition circuit configured to acquire a pair of images captured by using the endoscope; and 
 a processor, 
 wherein the processor is configured to:
 set, on an image among the pair of images, an interference area which is different from an observation target in the image with respect to a first characteristic, the first characteristic being a characteristic relating to color, and the interference area being set by (i) extracting at least one interference candidate area based on the first characteristic, and (ii) selecting the interference area from the at least one interference candidate area based on positional information of the at least one interference candidate area in the image and an occupation percentage of areas having pixels with luminance values equal to or higher than a threshold value in the at least one interference candidate area, and 
 perform correction on the image, the correction comprising (i) specifying pixels in the image corresponding to the interference area as processing targets, and (ii) performing image processing to reduce luminance values of the pixels in the image specified as the processing targets, and 
 
 wherein the selecting the interference area comprises selecting, as the interference area, an interference candidate area that is in contact with a side of the image and that extends from a peripheral edge of the image towards an inside of the image.